Catalytic method of preparing unsaturated aldehydes and acids



United States Patent Claims. (Cl. 260-533) This is a division of Ser.No. 338,617, now US. Patent No. 3,228,890.

This invention relates to a new and useful catalyst and to a method ofpreparing unsaturated aldehydes and unsaturated carboxylic acids byoxidation of unsaturated hydrocarbons at an elevated temperature andmore particularly pertains to a catalyst comprising a mixture of amolybdenum oxide, tellurium oxide and a manganese phosphate in a molarratio of 100 M00 10-100 TeO and 10-100 of a manganese phosphate and to amethod of preparing acrolein, methacrolein, acrylic acid or methacrylicacid by passing vapors of propylene or isobutylene and an oxygencontaining gas through the catalyst at a temperature of from about 325C. to about 550 C. The catalyst can also be designated as with the Pbeing in the form of a phosphate i.e. each P is attached to 3 or 4oxygen atoms.

Numerous attempts have been made in the past to prepare products ofhigher oxidation state from hydrocarbons, especially from the normallygaseous hydrocarbons. However, all prior catalysts and procedures foroxidizing monoolefinic gaseous hydrocarbons to monolefinicallyunsaturated aldehydes or monoolefinically unsaturated carboxylic acidswith the same number of carbon atoms as the hydrocarbon having seriousshortcomings. The catalysts either have a very short active life, orthey convert only a portion of the hydrocarbon to desired end groups perpass; or they oxidize the hydrocarbon excessively to form highproportions of carbon monoxide or carbon dioxide or both; or they arenot sufiiciently selective, so that the hydrocarbon molecule is attackedat both the olefinic unsaturation and at a methyl group; or theoxidation of the olefin does not proceed beyond the aldehyde stage.

It is therefore unexpected to find a catalyst that will convert fromabout 70 to 100% of a gaseous ,rnonoolefin such as propylene orisobutylene per pass to yield very high proportions of acrolein,methacrolein and acrylic acid or methacrylic acid. It is also unexpectedto find a catalyst that produces a wide ratio of olefinic aldehyde tomonoolefinically unsaturated carboxylic acid by controllable changes inreaction conditions or catalyst composition. It is possible to attainmol percent efiiciencies of 1.4 to 53 for the aldehyde and 10.8 to 72.1for the unsaturated carboxylic acid. Usually when the efiiciency forconversion of the hydrocarbon to aldehyde is high the efliciency for theconversion to acid is low and vice versa. This provides a great degreeof flexibility in the process, so as to provide means for obtaining aproduct mix that is needed at any particular time during operation.

A further unexpected feature is the unusually long active life of thecatalyst.

The oxidation of propylene to the corresponding aldehyde and acid ismore effective than the oxidation of isobutylene.

ice

THE REACTANTS The only essential reactants are (1) propylene orisobutylene and (2) an oxygen containing gas, which can be pure oxygen,oxygen enriched air or air without addition-a1 oxygen. For reasons ofeconomy, air is the preferred oxygen containing reactant.

Stoichiometric ratios of oxygen to olefin for the purpose of thisinvention are 1.5 to 1. Slightly lower amounts of oxygen can be used ata sacrifice of yield.

It is preferred, however, to use 33 to 66% excess oxygen. Larger excessdoes not impair the yields of aldehydes and acids, but for practicalconsiderations and excess much above 100% Would result in therequirement of extremely large equipment for a given productioncapacity.

The addition of steam into the reactor along with the hydrocarbon andoxygen containing gas is desirable but not absolutely essential. Thefunction of steam is not clear, but it does seem to reduce the amount ofcarbon monoxide and dioxide in the effluent gases.

Other diluent gases can be used. Surprisingly, saturated hydrocarbonssuch as propane are rather inert under the reaction conditions.Nitrogen, argon, krypton or other known inert gases can be used asdiluents if desired but are not preferred because of the added cost.

THE CATALYST AND ITS PREPARATION There are several methods for thepreparation of the catalyst, which can be supported or unsupported.

It is possible to dissolve each of the starting ingredients in water andcombine them from the aqueous solutions or the ingredients can be dryblended. Because of the more uniform blend obtained by the solutionprocedure, it is preferred.

The general procedure for preparing a catalyst from Water solubleingredients is to dissolve the requisite amount of a molybdenum salt, atellurium salt and a manganese salt in water. Add the requisite amountof phosphoric acid to the manganese salt solution. Add the telluriumsalt solution to the molybdenum salt solution and then add the manganesesalt-phosphoric acid mixture to the molybdenum-tellurium salt mixture.The catalyst is then dried and baked at 400 C. for about 16 hours.

Supported catalysts can be prepared by adding a dry support or anaqueous slurry thereof to the aqueous solution of catalyst or theaqueous catalyst ingredients can be added to the slurry of the support.

Alternatel-y a slurry of the catalyst ingredients can be prepared inwater, then dried and baked. For supported catalysts the aqueous slurryof the catalyst ingredients can be added to an aqueous suspension of thesupport or vice versa, and then dried and baked.

Another method is to blend the dry ingredients and then mix themthoroughly. The main difliculty is to obtain thorough blending anduniform particle size.

Specific procedures for making catalysts are as follows:

(a) Dissolve 105.96 g. of (NH Mo-;O -4H O in 272 ml. water at 5055 C.

(b) Dissolve 53.76 g. NH TeO in 900 ml. water at 50-55 C. and add to themolybdate solution with stirring. The mixture may become cloudy, but noprecipitate is formed.

'(c) Dissolve 79.19 g. MnCl -4H O in 40 ml. water and add 46.2 g. of HPO thereto.

Add the mixture described under (c) to the mixture of the ammoniummolybdate and ammonium tellurate. No precipitate is formed but the finalmixture remains cloudy.

If the catalyst is to remain unsupported, the mixture is evaporated todryness on a steam bath, heated at 150- 200 C. for about an hour andthen about 16 hours at 400 C. Then the catalyst is cooled, ground andsieved. For fixed bed systems a 1018 mesh (U.S. sieve) size is used. Forfluid bed systems the catalyst should be 80325 mesh (-U.S. sieve).

If the catalyst is to be supported the aqueous solution of ingredientscan be added to an aqueous slurry of the support or vice versa, prior todrying. The procedure after drying is the same as that alreadydescribed.

Thus, to the aqueous catalyst ingredients 240 g. (1.2 mols) of acolloidal silica (Ludox HS.) are added slowly with stirring. Stirring iscontinued for about /2 hour prior to drying.

This procedure is a variant of Procedure I.

(a) Prepare a slurry of 43.189 g. M (99.5% purity).

(b) Make a slurry of 15.961 g. TeO (technical) in water and blend witha) above.

(c) Dissolve 39.584 g. MnCl -4I-I O in water and add Blend this mixturewith the slurry of M00 and TeO Mix thoroughly and then dry and bake, or,if desired, add 120 g. Ludox HS. to the catalyst before drying. LudoxH5. is an aqueous colloidal dispersion of microspheroidal silica in aconcentration of 3035% SiO Another procedure is to add the mixturedescribed under (c) to the Ludox and then add the requisite amount ofTeO and M00 as a slurry.

Also, the ingredients can be added to the Ludox individually if desired.

III

In this procedure the ingredients are precipitated on blending.

(a) Dissolve 105.96 g. of ammonium molybdate in water at about 50 C.

(b) Dissolve 31.922 g. TeO in concentrated HCl and filter if necessary.

Add the tellurium salt solution to the ammonium molybdate solution. Aprecipitate forms.

(c) 'Dissolve 79.168 g. MnCl -4H O in Water and add 462 g. of 85% H POAdd this mixture slowly to the precipitated ammonium molybdate-TeOmixture.

Dry on a steam bath and bake for 16 hours at 400 C. Thereafter, thecatalyst is ground to the desired mesh size and sieved. For supportedcatalysts an aqueous slurry can be added to the catalyst ingredients, orvice versa, prior to drying and baking.

The fourth method is to grind M00 TeO and a manganese phosphate to theproper particle size and then thoroughly mix the dry powders. Themixture can be added to an queous slurry of a support or vice versa andthereafter dried and baked.

The exact chemical structure of the catalysts made by the aboveprocedures is not known, but catalysts with molar ratios of 100 Mo, -100Te and 10-l00 of a manganese phosphate can be used for oxidizing themonoolefinic hydrocarbon to aldehyde and/ or carboxylic acid. Thecatalyst contains chemically bound oxygen so that the generic formulacan be written as M00 TeO 10-100 Mn P O or other Mn phosphate 10400. Thephosphate can be a P0, radical, a pyrophosphate or a polyphosphate.

Among the suitable supports are silica, silica containing materials,such as diatomaceous earth, kieselguhr, silicon carbide, clay, aluminumoxides and even carbon, although the latter tends to be consumed duringthe reaction.

The preferred catalyst is one having a ratio of 100 M00 33.25 TeO and33.25 Mn P O because it gives the highest yields of desired products andthe preferred support is silica, because of its low cost and goodfluidizing characteristics.

REACTION CONDITIONS The reaction can be carried out in either a fixed orfluidized catalyst bed.

The reaction temperature can range from about 300 to 450 C. for theoxidation of propylene but the preferred range is from about 350 toabout 425 C. Below 350 C. the conversion per pass is lower thandesirable and low temperature tends to produce more aldehyde thandesired. Usually, a longer contact time is needed at lower temperaturesto obtain the yields of desired products obtainable at highertemperatures.

Above 425 C. in the propylene oxidation some of the desired end productsappear to be oxidized to carbon oxides. This is much more apparent at450 C. For the isobutylene oxidation temperatures of 375-550 aredesirable with the preferred range being 475-525 C.

The molar ratio of oxygen to propylene or isobutylene should be at least2 to 1 for good conversion and yields, but ratios with some excessoxygen, 33 to 66 mol percent is even more desirable and is preferred.There is no critical upper limit as to the amount of oxygen, but whenair is used as the oxygen containing gas it becomes apparent that toogreat an excess will require large reactors, pumping, compressing andother auxiliary equipment for any given amount of desired end product.It is therefore best to limit the amount of air to provide a 33 to 66%excess of oxygen. This range provides the largest proportion of acid,under given reaction conditions. Also, since care is needed to avoid anexplosive mixture the limiting of air aids in that direction.

The molar ratio of steam to propylene or isobutylene can range from 0 toabout 5, but best results are obtained with molar ratios of about 3.2 to4.25 per mol of olefin and for this reason are preferred.

The contact time can vary considerably in the range of about 2 to 70seconds. Best results are obtained in a range of about 8 to 54 secondsand this range is preferred. Longer contact times usually favor theproduction of acid at any given temperature.

The particle size of catalyst for fixed bed and fluid bed systems hasalready been described.

The reaction can be run at atmospheric pressure, in a partial vacuum orunder induced pressure up to 50-100 p.s.i. Atmospheric pressure ispreferred for fixed bed systems and a pressure of 1 to p.s.i. for fluidbed reactions. Care is needed to operate at a pressure which is belowthe dew point pressure of the unsaturated acid at the reactiontemperature.

The data in the examples show that wide variations in percentages ofunsaturated acids and aldehydes can be obtained with a single catalyst,using fixed ratio of reactants but changing the temperature and/orcontact time. Further variation is obtainable by controlling the othervariables in the reaction including the catalyst compositions.

The examples are intended to illustrate the invention but not to limitit.

Example I A series of runs was made in a fixed bed reactor of a highsilica (Vycor) glass tube 12 inches long and 30 mm. outer diameter. Thereactor had three inlets, one for air, one for steam and one forpropylene. Three external electrically operated heating coils were woundon the reactor. One of'the coils extended along the entire length of thereactor and each of the remaining coils extended only about one half thelength of the reactor.

Outlet vapors were passed through a short water cooled condenser.Uncondensed gases were passed through a gas chromatograph (Perkin-Elmermodel 154D) and analyzed continuously. The liquid condensate was Weighedand then analyzed for acrylic acid and acrolein in the gaschromatograph.

The reactor was filled to about 90% of its capacity with 170 ml. of acatalyst made by Method IV described above, using a ratio of 100 M 33.25TeO and 33.25 Ml'lzPzOq, Empirically the catalyst is and the P ispresent as P 0 The catalyst was not supported and had a mesh size of10-18 (U.S. Sieve).

Steam at a temperature of 200-250 C. was first passed into the reactor.Then propylene and air were separately fed into the stream of watervapor. This mixture then passed through a pre-heater and entered thereactor at about ZOO-250 C. The reactor was pre-heated to about 285 C.before the gas feed was begun.

The ratio of reactants was about 2.955 mols of oxygen and 4.16 mols ofsteam per mol of propylene, Cold contact time was 54 seconds.

The reaction temperature was varied as the reaction proceeded.

The table below summarizes the data obtained in these runs:

Acr.=Acrolein; AA=Acrylic Acid.

Repetition of Run 5 showed a yield of 3.3% acrolein and 70.8% acrylicacid.

In this set of experiments the only variable was the reactiontemperature. It is apparent that if acrylic acid is the desired endproduct the reaction should preferably be held at about 405 to 415 C. Ifacrolein is the desired product lower tempertaures of 350 C. or slightlybelow are preferred. Run No. 2 shows a combined efliciency of 84.5% witha ratio of acrolein to acrylic acid of about 1 to 1.2. Run No. 5 showsunusually good efficiency for acrylic acid production. If acrylic acidis the end product desired with a minimum of acrolein the conditions ofthis reaction can be followed.

Example II The catalyst and feed ratios were the same as those describedunder Example I. The cold contact time was 27 seconds. The reactor wassimilar to that described in Example I, but it had a length of 6 inchesinstead of 12. The amount of catalyst used was 85 ml.

A run at 400 C. showed 81.2% conversion of propylene with a mol percentyield, based on propylene con- Example III The reactor, catalyst andcatalyst volume were identical to those disclosed in Example I. Themolar ratio of oxygen (supplied as air) to propylene in all runs was 3to l, and the steam-propylene ratio was 4.25 to 1, on a molar basis.Cold contact time in each case was 41 seconds.

The data obtained are recorded below:

Mol percent Yield Mol percent Run Temp., Mol Percent on PropyleneEfiiclency N 0. C. Propylene Converted Converted Acr. AA Aer. AA

Run No. 2 shows a combined efliciency of 87.6, which is unusually highin view of the fact that there are numerous competing reactions going onconcurrently, including the oxidation of the hydrocarbon to carbonmonoxide and carbon dioxide.

Example IV In order to show the effect of water vapor, a series of testswas made using a feed containing 3 mols of oxygen (supplied as air) permol of propylene. The reactor, catalyst and catalyst volume were thesame as described in Example I.

The data obtained in these runs are shown in the table below:

ene was complete in all instances.

The data show that the presence of moisture is desirable but notessential to good yields of end products desired.

Example V The reactor, catalyst and catalyst volume were the same asdescribed in Example I. The main. variable was the difference in theamount of oxygen in the feed gases. Data obtained are tabulated below:The oxygen was supplied as air.

Mol percent Yield Contact Temp., M01 percent on Propylene O /CaHnHgO/OaHe Time, C. Propylene Converted Sec. Converted Aer. AA

verted, of 63 for acrolein and 27.5 for acrylic acid. The Example VIrespective mol percent eificiencies are 51.1 and 22.4.

Another test made at 422 C. converted 95.4% of the propylene with a molpercent yield of acrolein of 46.3 and acrylic acid of 43.0. Therespective mol percent efiiciencies are 44.1 and 41.1.

This example shows that by reducing catalyst volume to one half that inExample I and also reducing the contact time excellent efficiencies areobtainable.

This example shows the use of catalysts with variable compositions. Eachcatalyst was prepared by Procedure III, detailed above. The amount ofcatalyst employed was ml. in the 12 inch reactor. In each run the oxygen(fed as air) to propylene ratio was 3 to 1 and 4.25 mols of steam werefed per mol of propylene. The cold contact time was 41 seconds.

Mol percent Yield M01 percent M01 ratio of Percent on PropyleneEfliciency Catalyst per Temp, C Propylene Converted 100 mols MoConverted Acr AA Acr AA 'IeO2 MllgP207 100 3. 7 49.7 100 4. 2 52. 5 94.4 50. l 33. 4 100 25.0 49. 3 100 9. 1 55. 8 93. 4 52. 7 32. 100 40. 545.0 100 25. 5 54. 5 94. 8 37. 8 32.1 100 17. 5 54.0 100 12. 1 55. 498.8 38.7 48. 3 100 29. 8 57. 9 100 14. 7 64. 6 100 15. 4 62. 2 95.2 43.2 33. 5 100 23.7 54. 5 100 5. 2 70. 2 100 46. 5 30.8 100 27 1 46. 4 10010. 2 58. 2 100 8. 5 61. 2 100 38. 6 44. 9 100 30. 5 53.0 100 36. 2 45.2 100 14. 2 50. 9 96. 8 38. 0 31. 5 100 21. 9 45. 9 100 4. 3 54. 6 100l. 4 57. 2 91.0 68. 5 21.3 100 48. 8 39. l 100 37. 7 49.0 100 28. 3 54.I 99. 2 53. 4 28. 4 100 44.2 37.0 100 10. 2 64. I 100 4. 7 58. 8

The above data show that a range of from 10-80 mols Example VIII TeO and10-80 mols of a manganese phosphate per 100 mols of molybdenum compoundcan be employed to obtain good yields of acrolein and acrylic acid fromthe oxidation of propylene.

Example VII The runs of this example were made with an unsupportedcatalyst prepared by dissolving ammonium molybdate and ammoniumtellurate in water and blend- A catalyst was prepared by moistening129.6 g. of M00 (99.5%), adding 47.88 g. TeO 42.56 g. MnO and 69.2 g. of85% H PO in the order named. The mixture was thoroughly blended, driedand heated for 16 hours at 400 C. The catalyst was then ground andscreened. Particles with a mesh size of 1018 (U.S. Sieve) were used. Thereactor was 12 inches long. It was charged with 170 ml. of catalyst. Thedata obtained with this catalyst are summarized below:

M01 Percent Yield Mol Perce nt Contact Temp, M01 Percent on PropyleneElficienoy 02/031173 H2O/C H Time, C. Propylene Converted Sec. ConvertedAer. AA Aer. AA

ing the two solutions and thereafter adding an aqueous 'Example IX M01Percent Mol Percent Yield on Mol Percent Temp., C Propylene PropyleneConverted Elficiency Converted 7O Aer AA Aer. AA

This example shows results obtained in a fixed bed system with a silicasupported catalyst. Catalyst A was prepared by adding the requisteamount of M00 (99.5% pure) in aqueous slurry to a colloidal silica'(Ludox H.S.) with stirring, then a slurry of TeO was added withstirring and finally a solution of MnCl in H PO was added. The mixturewas stirred, dried, and baked at 400 C. Catalyst B was prepared bymaking a solution of ammonium molybdate and ammonium tellurate in waterand adding this to a colloidal silica which had some added ammoniumhydroxide to prevent precipitation of the catalyst ingredients. Then anaqueous solution of MnCl and H PO was added. The mixture was stirredwell, dried and baked at 400 C. for 16 hours. The reactor used was 6inches long. It was filled with 85 ml. of catalyst. The molar ratio ofingredients in each catalyst was M0 33.25 TeO 33.25 Mn P O and 200 SiOM01 Percent Efficiency Aer. AA

M01 percent Yield on Propylene Converted Me! Contact Temp, Percent Time,C. Propylene Converted Data obtained are tabulated below:

Catalyst A LQRm 5 9m1 4 54 544 3889 823 A Rm 5 0m? animate 05005024 1717 wuwaanae.

M01 Percent Yield Mol Percent on Propylene 0. Conversion ConvertedPropylene Aer. AA

a surface area of 3-6 sq. meters/ g. and an average water absorptioncapacity of 90 g./100 g. of Celite.

The unsupported catalyst was made by Procedure III ported ondiatomaceous earth, This support provided SH- 20 descrlbed above- Inthese runs the reactor was a high silica glass cylinder with an CD. of38 mm, and height of 5 ft. It was filled to a height of 10.5 inches forthe unsupported catalyst and to -a height of 24 inches for the supportedcatalyst. In all 5 cases the catalyst was fluidized by first injectinghot air into the reactor and then adding the requisite amounts of steamand propylene. The gases were preheated to about 250 C. prior toentering the reactor. The reactor was heated externally with electricalresistance wire, and the reaction temperature was controlled by use ofrheostats to regulate the flow of current through the electrical heatingwires.

The data obtained in the runs are given below:

UNSUPPORTED CATALYST Contact Temp, 2/ 2 11 HQO/CEHB Tsllele,

Catalyst B All the above examples illustrate the use of the newcatalysts in fixed bed systems. The following are examples The supportedcatalyst employed in the fluidized bed was made as follows:

211.92 g. of ammonium molybdate were dissolved in 220 ml. H O at C. and132 g. of diatomaceous earth (Celite V) were added and stirred untilthorough blending was obtained.

102.2 g. of TeO were dissolved in 216 ml. of warm concentrated HCl and105 g. of Celite V were added thereto.

in fluid bed systems. In each instance the catalyst was supperiorfluidizing characteristics and provided better yields of desiredproducts than the colloidal silica supported catalysts.

9345804400 O 0 5 & A LA SM 6463m3311n 8iA O O O 2 11222%2%N 5464133740SUPPORTED CATALYST Example X In this example two difierent catalystswere used, A ad a molar ratio of M00 3 3.25 TeO; and 33.25 of Mn (PO andB had a molar ratio of 100 M00 33.25 TcO and MH5(P3010)2.

Mol Percent Yield Mol Percent on Propylene Efliciency Converted Aer. AAAer. AA

ably.

Contact Tom Time, Sec.

il/ 3 3 Kilo/C3115 To a solution of 158.3 g. of MnCl in 140 ml. of waterwere added 92.4 g. of 85% H PO (aqueous) and g. Celite V were added tothe mixture.

The tellurium oxide-HCl mixture was added to the mixture containing themanganese salt and blended thoroughly and the ammonium molyb-date-Celitemixture was added last. The mixture was dried and baked at 400 C.

Celite V is a diatomaceous earth in granular form, with 60 h minorcristobalite structure. It has a bulk density of .39 g./cc., a skeletaldensity of 2.2 g./cc, determined in water,

32. 116 ill.

Example XI 1.5 to 4 mols of oxygen and up to 7 mols of water vapor permol of said monoolefinic hydrocarbon, at a temperature of from about 325C. to about 500 C., the said catalyst consisting essentially, on a molarbasis, of MO1uTe1 10Ml12 20P2 2n039 120 in each P is combined with 3 to4 atoms of oxygen and the Mn to P ratio ranges from 5Mn to GP to 3Mn to2P.

2. A method of preparing a mixture of claim 1 for In this exampleisobutylene was used as the olefin. The results show that the mostdesirable temperature for the oxidation of this olefin to methacroleinand methacrylic acid is higher than that for the oxidation of 5propylene, and also that the isobutylene is somewhat more resistant tooxidation than propylene, because it requires drastic conditions toobtain a high conversion of the olefin. Also, the yields andefiiciencies for isobuacrolein and y c d C mprising passing a mixturetylene oxidation are not as good as those obtained with of Propylene,and an Oxygen Containing g Containing propylene. from about 1.5 to 4mols of oxygen per mol of propylene The data below show results obtainedwith the catthrough a bed of a catalyst having the empirical formulaalyst at two different volumes. M0 Te Mn P O in which each P atom is 170ML. CATALYST VOLUME M01 percent Yield Mol percent Contact Temp, Percenton Isobutylene Eflicieney O /C H H1O/C H Time, C. Isobutylene ConvertedSec. Converted Aldehyde Acid Aldehyde Acid 85 ML. CATALYST VOLUME Thecatalyst had a molar ratio of 100 M00 25 T e0 combined with 3 to 4 atomsof oxygen and the Mn to and 25 Mn P O- P ratio ranges from 5Mn to 6P to3Mn to 2P, at a tem- Example XII perature of from about 350 C. to about450 C. An unsupported catalyst made by Procedure In is The method ofclaim 2 in which the Mn to P ratio ing molar ratios of ingredients suchthat the M00 Te0 and Mn P O was 1:1:1, was placed in the 12 inch fixedbed reactor hereinbefore described. The reaction mixture consisted of 1mol of propylene, about 3 mols of oxygen, supplied as air, and 4.2 molsof water vapor. The reaction temperature was 390 C. and the coldconacrolem and acryhc acid comPrfsmg Passmg a fixture tact time was 54seconds. All of the propylene was conof Propylene an oxygen contalmnggas contammg from sumed, with a yield of 3.0% acrolein and 61.5% ofacrylic about mols of oxygen Per mol of Propylene and up to 7 mols ofwater vapor per mol of propylene through 35 4. The method of claim 2 inwhich the catalyst has the empirical formula Mo10oTe33 25Mn66 5P66 5059925 and the P is present as P 0 5. A method of claim 2 for preparing amixture of acid.

For the purpose of this invention the hydrocarbons a bed of a catalystcompnsmg which are oxidized can be defined generically by the lvp 'n lvp 50599 25 4. formula from about 360 to about 425 C.

(C3904 6. A method of claim 1 for preparing a mixture of methacroleinand methacrylic acid comprising passing a mixture of isobutylene and anoxygen containing gas wherein it is also apparent that the end productsformed in an amount sufficient to provide from about 1.5 to about resultfrom the oxidation of only one methyl group on 3 mols of oxygen per molof isobutylene, through a bed the hydrocarbon molecule while theterminal CHFC of a catalyst comprising M010Te1 10 z 2o 2 2o a9-12oremains intact. in which the Mn to P ratio ranges from Mn to P to Mn Itis apparent to those Skilled in the art that there to P and in whicheach P is combined with 3 to 4 atoms are many variations in respect ofcatalyst, catalyst conf oxygen centration, and reactant ratios that canbe employed and 7 Thc method of claim 6 in which from about 1 to thatthe 1nvent1on shall not be limited except by the about 7 mols of watervapor per mol of isobutylene are claims.

The method of impregnating a silicic carrier with i m the mlxture whlch18 passed through the ca a yst.

individual ingredients of the catalyst system and there- 8 The method ofclaim 6 in which the catalyst is after combining the so impregnatedcarriers to complete the catalyst preparation is disclosed and claimedin patent g g g zififx m whlch the P 15 present fil d 111 t apphcatlonNO 380 683 6 J y 6 1964 m he name 9. A method for preparing a mixture ofunsaturated g' t' fi 6 monoolefinic aldehydes and monoolefinicmonocarboxylic 1. A method of preparing a mixture of unsubstitumd acidscomprising contacting a hydrocarbon selected from monoolefinic aldehydesand monoolefinic monocarboxthe gYOuP consisting of P py and isobutylene,and ylic id .b id ti f a th l group of a h d oxygen, in a molar ratio ofone mol of hydrocarbon and carbon having th stru ture 1.5 to 4 mols ofoxygen at a temperature from about H 325 to 500 C., with a catalystcomprising, in molar (CHM-l ratio, 100 M00 10-100 TeO and 10400 of amanga- CHaC=CHz nese phosphate. comprising passing through a catalystbed a mixture 10. The method of claim 9 wherein the hydrocarbon of gaseshaving a molar ratio of 1 mol of said monooleis propylene, the manganesephosphate is manganese finic hydrocarbon, an oxygen containing gascontaining pyrophosphate, the temperature is about 350 to about i3 14-425 C., the molar ratio of oxygen to propylene is at least FOREIGNPATENTS 2:1 present in air and there is also present from 0 to about839,808 6/1960 Great Britain 5 mois of steam per mol of propylene.

HENRY R. JILES, Primary Examiner. References Cum! 5 LORRAINE AWEINBERGER RICHARD K JACK UNITED STATES PATENTS SON, Examiners.2,649,477 8/1953 Jacobs et a1 260-533 3,192,259 6/1965 Fettefly et a1.260 533 D. E. STENZEL, S. B. WILLIAMS, Asszstam Exammers.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,392,196 July 9, 1968 Jamal S. Eden It is certified that error appearsin the above identified patent and that said Letters Patent are herebycorrected as shown below:

second occurrence, should read Column 2, line 12, "and", an Column 5, inthe table, first column, line 5 thereof, "416" should read 415 Columns 7and 8, in the table,

first column, line 23 thereof, "389" should read 398 Column 8, line 61,"requiste" should read requisite 12, line 44, after the formula, insertin which the P is present as P 0 at a temperature of Colum Signed andsealed this 16th day of December 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Ir.

Commissioner of Patents Attesting Officer

1. A METHOD OF PREPARING A MIXTURE OF UNSUBSTITUTED MONOOLEFINICALDEHYDES AND MONOOLEFINIC MONOCARBOXYLIC ACIDS BY OXIDATION OF A METHYLGROUP OF A HYDROCARBON HAVING THE STRUCTURE